1. Field of the Invention
The invention relates to materials consisting essentially of hydrocarbon characterized by at least two chain linear alkyl groups, which materials are useful as wax crystal modifiers for petroleum oils, such as pour depressants, flow improvers, etc. for fuel oils.
2. Prior Art
Kerosene, which acts as a solvent for n-paraffin wax, has traditionally been a component of middle distillate fuel oils. Recently, with the increased demand for kerosene for use in jet fuels, the amount of kerosene used in middle distillate fuel oils has decreased. This, in turn, has frequently required the addition of wax crystal modifiers, e.g. pour point depressant additives, to the fuel oil to make up for the lack of kerosene.
The more effective of these distillate oil pour depressants are copolymers of ethylene with various other monomers, e.g. copolymers of ethylene and vinyl esters of lower fatty acids such as vinyl acetate (U.S. Pat. No. 3,048,479); copolymers of ethylene and alkyl acrylate (Canadian Pat. No. 676,875); terpolymers of ethylene with vinyl esters and alkyl fumarates (U.S. Pat. Nos. 3,304,261 and 3,341,309); polymers of ethylene with other lower olefins, or homopolymers of ethylene (British Pat. Nos. 848,777 and 993,744); chlorinated polyethylene (Belgium Pat. No. 707,371 and U.S. Pat. No. 3,337,313); etc.